21682921536 has 112 divisors (see below), whose sum is σ = 64030758400. Its totient is φ = 7195101696.

The previous prime is 21682921523. The next prime is 21682921549. The reversal of 21682921536 is 63512928612.

21682921536 is a `hidden beast` number, since 2 + 16 + 82 + 9 + 21 + 536 = 666.

It is an interprime number because it is at equal distance from previous prime (21682921523) and next prime (21682921549).

It is a junction number, because it is equal to n+sod(n) for n = 21682921491 and 21682921500.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 357210 + ... + 413478.

It is an arithmetic number, because the mean of its divisors is an integer number (571703200).

Almost surely, 2^21682921536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21682921536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32015379200).

21682921536 is an abundant number, since it is smaller than the sum of its proper divisors (42347836864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21682921536 is a wasteful number, since it uses less digits than its factorization.

21682921536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56513 (or 56497 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The spelling of 21682921536 in words is "twenty-one billion, six hundred eighty-two million, nine hundred twenty-one thousand, five hundred thirty-six".